[The role of the static P-V curve under zero end-expiratory pressure in sustained inflation in patients with acute respiratory distress syndrome].

ABSTRACT

OBJECTIVE: To evaluate the value of static P-V curve under zero end-expiratory pressure (ZEEP) in predicting the effect of sustained inflation (SI) on hemodynamics, oxygenation and alveolar recruitment in patients with acute respiratory distress syndrome (ARDS). METHODS: Static P-V curve was measured under positive end-expiratory pressure (PEEP) in all the patients 2 h afer PEEP was applied. Patients who experienced more than 20% increase in PaO(2)/FiO(2) were considered as responders to SI. RESULTS: (1) The static P-V curves in responders consistently showed a concave pattern with c-2d >or= 0 cm H(2)O (1 cm H(2)O = 0.098 kpa) and c >or= 18 cm H(2)O, while those in non-responders showed a convex pattern with c-2d < 0 cm H(2)O or c < 18 cm H(2)O. (2) After SI, decrease of Q(s)/Q(t) (P = 0.006) was found in responders, but not in non-responders (P = 0.339). The amount of recruited volume was significantly higher in responders than in non-responders after SI [(241 +/- 111) ml vs (29 +/- 46) ml, P = 0.036]. CONCLUSION: The static P-V curves under ZEEP exhibited different patterns in responders and non-responders to SI in ARDS patients, and may be of value in predicting the response to SI.